Hydrocarbon extraction by oleophilic beads from aqueous mixtures

ABSTRACT

A system for the recovery of hydrocarbonaceous material, said hydrocarbonaceous material being in an aggregate mixture in a water slurry, said system comprising: (a) a means for centrifuging to remove liquid material from the slurry so as to obtain a water phase, a hydrocarbon phase and an aggregate solid phase; (b) a mixing vessel and means for delivery to said mixing vessel a measured quantity of said aggregate solids, water and a measure quantity of buoyant beads having a bare oleophilic surface (c) agitation means for agitating said aqueous mixture in said mixing vessel so as to obtain product buoyant beads having hydrocarbonaceous material associated therewith; and (c) recovery means for recovering product buoyant beads.

FIELD OF THE INVENTION

The present invention relates to methods and systems for recoveringfluid type (e.g. liquid) hydrocarbons from both naturally-occurring andman-made mixtures of hydrocarbons and mineral substrates; also possiblyfrom mixtures of fluid type (e.g. liquid) hydrocarbons and water (i.e.no mineral substrates) such as, for example, from wastewater comprisinghydrocarbonaceous material. In particular, the present invention relatesto methods and systems for processing hydrocarbon-containing geologicmaterial or ores (including; tar sands, oil sands, oil sandstones, oilshales) as well as petroleum contaminated soils/and fluids to recoverpetroleum-like hydrocarbons, and especially bitumen/kerogen/and/or crudeoil and/or fractions, therefrom and to render the water and/or mineralsubstrate residues suitably low in hydrocarbons, forenvironmentally-acceptable disposal; and most particularly to a methodand system for separating bitumen from particulates in tar sand and oilsand-grains, using buoyant oleophilic beads. As used hereinafter, theterm “tar sands” shall be taken to mean any or all of the abovehydrocarbonaceous material containing ores. As disclosed, for example,in Canadian Patent No. 975,697 issued on Oct. 7, 1975 to Davitt H. Jamestailing pond contents, referred to as sludge therein, may be a potentialsource of bitumen.

It is to be understood herein that in relation to the expression “bareoleophilic surface” and the like, such a (bare) surface is to beunderstood as being a “film free or essentially film free surface” andin particular as being a “surface devoid of or essentially devoid of anyhydrocarbon or solvent (outer) film”. It is in particular to beunderstood herein that the expressions “film free or essentially filmfree surface” and “surface devoid of or essentially devoid of anyhydrocarbon or solvent (outer) film” and the like are to be understoodas qualifying a (bare oleophilic) surface etc. as being a surface etc.able to be (directly) associated with a hydrocarbonaceous material (forthe purposes) as described herein, e.g. without the application orintervention of an intermediate hydrocarbon film or layer being (first)applied to such surface etc. For example such a surface may be a surfacewhich has no film of solvent or if such film of solvent is present, itmay be present in essentially not more than 2% solvent weight by weightof the beads and in particular the amount of solvent following thedrying stage may, for example, be not more than about 0.5% by weight ofsolvent by weight of the beads.

In the intended application of attaching hydrocarbonaceous material tothe surface of suitable (buoyant) beads, such beads associated withhydrocarbonaceous material may, for example, be made bare ofhydrocarbonaceous film by volatilization (e.g. by the exploitation ofheat, vacuum, etc, including combinations thereof,) of (all) residualhydrocarbon liquids and/or solvents, and/or by means of centrifuging,and/or by microbial degradation such that the desired oleophilicproperties of the beads is (fully) restored, enabling them to bereintroduced to the process as recycled, fresh beads unaltered by anycross-contamination.

As used herein, the terminology “aggregate component” and any similarword(ing) shall be understood as referring to or as characterizing (oremphasizing) a “material”, etc. or any portion thereof as a mass ofindividual particles or elements of the same or varied size (e.g. thesize of the particles or elements may or may not be uniform and mayrange from microscopic granules to 10 cm and larger); it is also to beunderstood that the particle size distribution of any particular“material”, etc. may be different from that of another “material”, etc.which is part of an aggregate component”.

As used herein, the terminology “aggregate component” and the like shallalso be understood as referring to but not limited to superficial earthcrust material, whether natural or man made (i.e. unconsolidated mantle,soil, etc.), namely aggregate material including but not limited toaggregate material disposed on dry land masses (e.g. soil aggregatematerial); sedimentary aggregate including any bottom sediments of freshor marine water systems; aggregate material which has an organic matterportion derived for example from tar sands, oil shale, etc.; aggregatematerial derived from human activities, such as, for example, mineralaggregate materials, fill aggregate materials as well as sedimentsarising in water-ways; etc.

Thus as used herein, the terminology “soil” includes all forms ofparticulate matter, such as, for example, clay, fines, sand, rock,humus, etc. and in particular for example, soil particles and embankmentmaterial particles.

It is to be understood herein that the expression “hydrocarbonaceousmaterial” or the like is a reference to a liquid material; such liquidmaterial may have a low (e.g. 1 centipoise) to (very) high viscosity(e.g. 10.sup.6 centipoise); e.g. a viscosity in the range of from 10centipoise to 10.sup.6 centipoise.

It is further to be understood herein that the expression“hydrocarbonaceous material” or the like is a reference to naturallyoccurring and/or man-made fluid (i.e. liquid) material including but notlimited to hydrocarbon type organic materials. In general, theexpression “hydrocarbonaceous material” or the like is to be understoodas being a reference to any type of organic material comprising hydrogenand carbon provided that such material is able to be picked-up by thesurface of beads as described herein; in particular such materials whichare (at least partially) water insoluble or water immiscible. Thus, theexpression “hydrocarbonaceous material” or the like is in particular tobe understood as being a hydrocarbon type organic material consisting ofhydrogen and carbon.

A “hydrocarbonaceous material” may be associated with inorganic type(e.g. mineral type) substrates, which may, for example, constitute inaddition to hydrocarbons, oleophilic (solid) particles. Such oleophilic(solid) particles may be organic, and may comprise asphaltenes, lowgrade coal, kerogen, etc. . . . A “hydrocarbonaceous material” may befound in hydrocarbon-containing geologic material or ores including tarsands, oils sands, oil sandstones, oil shales and petroleum contaminatedsoils.

It is further understood that the hydrocarbonaceous material recovered(as described herein) from the product beads by the use of a hydrocarbonsolvent to recover hydrocarbonaceous material there from (e.g. as acomponent of a hydrocarbon fluid (i.e. liquid) mixture comprisingrecovered hydrocarbonaceous material and said hydrocarbon solvent), maybe suitable for refining and the amount of hydrocarbon solvent presentin the mixture may be such that the viscosity of the hydrocarbonaceousmaterial may be manipulated (e.g. reduced) so as to provide an API valueof at least 12 (e.g. an API of 16 or higher) which is suitable forpipeline transportation to a refinery.

BACKGROUND OF THE INVENTION

Procedures for separating bitumen from mined oil sands are known. A hotwater method is for example, disclosed in Canadian Patent No. 841,581issued May 12, 1979 to Paul H. Floyd, et. al.; in accordance with thispatent bituminous sands are jetted with steam and mulled with a minoramount of hot water and sodium hydroxide in a conditioning drum toproduce a pulp which passes from the conditioning drum through a screenwhich removes debris, rocks and oversize lumps to a sump where it isdiluted with additional water. It is thereafter carried into aseparation cell.

In the separation cell, sand settles to the bottom as tailings which arediscarded. Bitumen rises to the top of the cell in the form of abituminous froth which is called the primary froth product. The frothproduct may be combined with a hydrocarbon diluent such as naphtha. Theresultant mixture may be centrifuged to obtain a final bitumen productthat is suitable for refining into a synthetic crude oil.

Various methods for preparing oil sand slurries are also taught in theprior art; see for example Canadian (CA) Patent No. 918,588 issued onJan. 9, 1973 to Marshall R. Smith, et. al., and U.S. Pat. No. 3,968,572issued on Jul. 13, 1976 to Frederick C. Stuchberry.

CA 2212447 discloses the use of oleophilic free bodies and a hydrocarbonsolvent film applied thereto to collect the oil phase as disclosed inthe patent.

It would, for example, be advantageous to have an alternate means forrecovery of hydrocarbonaceous material from substances comprising forexample different types of (viscous) hydrocarbon oils and mineralparticles. It would in particular be advantageous to be able to recoverbitumen mixtures such as for example mined tar sand slurries, tar sandtailings, middlings and tailings pond sludge; viscous hydrocarbonsdeposited on sands or water surfaces as a result of oil spills; oil andwater emulsions created by steam injection into tar sands or heavy oildeposits or other oil recovery techniques; mineral deposits in low gradeores mined dry and mixed with water or dredged materials from streams,lakes beds, river bottoms and the like.

U.S. Pat. No. 8,440,727 discloses a system and method for recoveringhydrocarbonaceous material from either a water or from a solid base.Furthermore, the amount of material recycled in this patent could beimproved up. It would be advantageous to provide a system capable ofrecovering hydrocarbonaceous material from a slurry, and also to be ableto recycle more material.

SUMMARY OF THE INVENTION

The invention in an aspect relates to the use (e.g. reuse) of buoyantbeads having a (bare) oleophilic surface able to associate with (i.e.pick-up) hydrocarbonaceous material (e.g. bituminous material) forrecovery thereof. Such (bare) oleophilic surface has the advantage ofbeing able to take up a wide range of hydrocarbonaceous material.

Thus, in a particular aspect the present invention relates to the use ofbuoyant beads having a bare oleophilic surface to recoverhydrocarbonaceous material from an aqueous mixture comprising water andhydrocarbonaceous material.

The invention in accordance with another aspect exploits a (hydrocarbon)solvent (e.g. a solvent as described herein—e.g. a substance comprisingtoluene, xylene, naphtha, hexane, pentane and the like as well asmixtures thereof) to recover hydrocarbonaceous material from productbuoyant beads (e.g. as described herein). However, in accordance with aparticular feature of this aspect the (hydrocarbon) solvent need, forexample, not be (e.g. wholly) separated from the recoveredhydrocarbonaceous material for recycling but may instead be used orexploited to perform the function of a diluent component to facilitatepumping of recovered hydrocarbonaceous material to a downstreamprocessing plant or to a storage tank(s) for subsequent transport tosuch a downstream processing plant (i.e. by pipeline or by tankertruck).

In accordance with the present invention the buoyant beads (or freebodies) may take any suitable or desired form keeping in mind thepurpose thereof. Thus the buoyant beads may be in the form of spheres,spheroids, pebbles, teardrops, rods, discs, saddles, or of anothershape, simple or complex, which is effective in searching out dispersedphase particles in the mixture. The buoyant beads (e.g. free bodies) maybe solid, hollow, or apertured. They are preferably of a smoothnon-porous surface. The buoyant beads (e.g. free bodies) may be cast,molded, formed or fabricated in other ways. Oleophilic free bodies maybe made with oleophilic materials or they may be made from othermaterials and then covered with a (solid) layer of an oleophilicmaterial.

Any oleophilic material may be used herein keeping in mind (see below)that the invention in an aspect relates to the use (e.g. reuse) ofbuoyant beads having a “bare” oleophilic surface able to associate with(i.e. pick-up) hydrocarbonaceous material (e.g. bituminous material) forrecovery thereof. Examples of suitable oleophilic materials that may beused in the fabrication of oleophilic buoyant beads of the presentinvention free bodies are neoprene, urethane, polypropylene, plasticsand artificial rubbers, see CA patent 1144498, CA patent 2212447, U.S.Pat. No. 3,399,765, U.S. Pat. No. 4,236,995, U.S. Pat. No. 4,406,793,U.S. Pat. No. 4,511,461, etc.

The use of oleophilic adhesion techniques of the present invention mayfor example be exploited for recovering bitumen from mined tar sands,for recovering other hydrocarbons from aqueous mixtures (e.g. fromwastewater) and for recovering oleophilic surfaced mineral particles.

The present invention in accordance with an aspect thereof provides amethod for the recovery (or separation) of hydrocarbonaceous materialfrom water, said hydrocarbonaceous material being a liquid material,said method comprising the steps of:

(a) agitating an aqueous mixture comprising water, saidhydrocarbonaceous material and buoyant beads having a bare oleophilic(i.e. film free or essentially film free) surface (e.g. a surface devoidof or essentially devoid of any hydrocarbon or solvent (outer) film,e.g. beads for which at least the (i.e. exposed/outer) surfaces are ofoleophilic material) so as to obtain product buoyant beads havinghydrocarbonaceous material associated therewith (i.e. buoyant beads to(the (outer) surface of) which hydrocarbonaceous material is adhered);and (b) recovering product buoyant beads.

In accordance with the present invention for step (b) any suitable ordesired recovery technique may be exploited for the recovery of theproduct buoyant beads (i.e. keeping in mind the purpose thereof). Thus,for example, step (b) may comprise a bead flotation step for therecovery of product buoyant beads; step (b) may comprise a screeningstep whereby product beads are separated (i.e. strained) from othercomponents of the aqueous mixture using suitable screening means; step(b) may as desired comprise a combination of these or other (suitable)recovery techniques.

In accordance with the present invention a method for the recovery (orseparation) of hydrocarbonaceous material may as desired or necessaryfurther comprise

(c) contacting product buoyant beads from step (b) with a hydrocarbonsolvent so as to recover hydrocarbonaceous material therefrom; e.g. soas to recover a hydrocarbon fluid (i.e. liquid) mixture whereinrecovered hydrocarbonaceous material is a component thereof along withhydrocarbon solvent. The hydrocarbon solvent in step (c) may forexample, comprises at least one compound that is selected from the groupconsisting of naphtha, toluene, hexane and pentane.

In accordance with the present invention step (c) may also be carriedout so as to also obtain solvent washed beads. The recovery method mayoptionally (or as desired or as necessary) comprise treating solventwashed beads (in any suitable manner) so as to recover buoyant beadshaving the above mentioned bare oleophilic surface. Such recovered beadmay as desired or necessary be recycled for use in step (a) of therecovery method. In other words as may be understood, solvent washedbeads (e.g. beads free of the sought after hydrocarbonaceous material)may yet be associated with hydrocarbon solvent. Hence, a method (orsystem) of the present invention may further comprise (any type ofsuitable) means (e.g. heating) for separating such (retained) solventfrom the solvent washed beads to return the beads to their original(i.e. bare) state, (i.e. devoid of or essentially devoid of any residualhydrocarbon or solvent film) for re-use.

The buoyant beads may be of any suitable material; see above. Thebuoyant beads may for example be an organic co-polymer. The beads mayfor example be specifically designed and manufactured for any uniquedesired characteristics. The polymer of the beads may be a materialhaving suitable oleophilic and buoyancy characteristics keeping in mindthe purpose thereof; the beads may as desired also have hydrophobiccharacteristic. Thus beads may be used which take the form of a(naturally) hydrophobic and oleophilic co-polymer.

In accordance with a particular aspect of the present inventionhydrocarbonaceous material may be recovered from a hydrocarbon bearingcomposition comprising an aggregate component and a hydrocarboncomponent, the hydrocarbon component comprising hydrocarbonaceousmaterial. The aggregate component, may be as defined herein (i.e.above).

Thus the present invention also relates to a method for the recovery (orseparation) of hydrocarbonaceous material from a hydrocarbon bearingcomposition comprising an aggregate component and a hydrocarboncomponent, said hydrocarbon component comprising hydrocarbonaceousmaterial, said hydrocarbonaceous material being a liquid material, themethod comprising: (a) agitating an aqueous mixture comprising water,said hydrocarbon bearing composition and buoyant beads having a bareoleophilic (i.e. film free or essentially film free) surface (e.g. asurface devoid of or essentially devoid of any hydrocarbon or solvent(outer) film, e.g. beads for which at least the (i.e. exposed/outer)surfaces are of oleophilic material), so as to obtain product buoyantbeads having hydrocarbonaceous material associated therewith; (b)recovering product buoyant beads; and (c) contacting product buoyantbeads from step (b) with a hydrocarbon solvent so as to recoverhydrocarbonaceous material therefrom.

In accordance with the present invention a method for the recovery (orseparation) of hydrocarbonaceous material from a hydrocarbon bearingcomposition is provided wherein step (b) thereof may comprise a beadflotation step for the recovery of said product buoyant beads and saidproduct buoyant beads from step (b) may be contacted with a hydrocarbonsolvent so as to recover hydrocarbonaceous material therefrom.

In accordance with the present invention a method for the recovery (orseparation) of hydrocarbonaceous material from a hydrocarbon bearingcomposition is provided wherein step (b) thereof may comprise a beadflotation step for the recovery of said product buoyant beads and saidproduct buoyant beads from step (b) may be contacted with a hydrocarbonsolvent so as to recover therefrom a liquid hydrocarbon mixturecomprising recovered hydrocarbonaceous material and hydrocarbon solventand so as to obtain solvent washed beads

In accordance with the present invention a method for the recovery (orseparation) of hydrocarbonaceous material from a hydrocarbon bearingcomposition is provided wherein the solvent washed beads may be treatedto obtain recovered buoyant beads having a bare oleophilic surface andsaid recovered buoyant beads are recycled to step (a) thereof.

As mentioned above in accordance with the present invention thehydrocarbon solvent in step (c) nay comprise at least one compound thatmay be selected from the group consisting of naphtha, toluene, hexaneand pentane.

In accordance with the present invention the buoyant beads may have aspecific gravity in the range of from 0.080 to 0.35.

In accordance with the present invention the buoyant beads may have anaverage width in the range of from 5 to 20 millimeters.

In accordance with the present invention the buoyant beads may have aspecific gravity in the range of from 0.080 to 0.35 and an average widthin the range of from 5 to 20 millimeters.

In accordance with another aspect the present invention relates to asystem for the recovery of hydrocarbonaceous material from water, saidhydrocarbonaceous material being a liquid material, said systemcomprising:

(a) a mixing vessel for containing an aqueous mixture comprising water,hydrocarbonaceous material and buoyant beads having a bare oleophilicsurface (as defined herein)

(b) agitation means for agitating said aqueous mixture in said mixingvessel so as to obtain product buoyant beads having hydrocarbonaceousmaterial associated therewith; and

(c) recovery means for recovering product buoyant beads.

A system in accordance with the present invention may comprise recoverymeans which comprises means for the recovery of product buoyant beads bybead flotation (or any other suitable, desired or necessary technique).

A system in accordance with the present invention may further comprisebead solvent wash means for contacting product buoyant beads with ahydrocarbon solvent so as to recover hydrocarbonaceous materialtherefrom. A system in accordance with the present invention may inparticular further comprise bead solvent wash means for contactingproduct buoyant beads with a hydrocarbon solvent so as to recovertherefrom a liquid hydrocarbon mixture comprising recoveredhydrocarbonaceous material and hydrocarbon solvent and so as to obtainsolvent washed beads.

A system in accordance with the present invention may further comprisemeans for treating solvent washed beads to obtain recovered buoyantbeads having a bare oleophilic surface (as defined herein).

A system in accordance with the present invention may further comprisemeans for recycling recovered buoyant beads having a bare oleophilicsurface (as defined herein) to the mixing vessel.

The present invention in particular relates to a system for the recoveryof hydrocarbonaceous material from a hydrocarbon bearing compositioncomprising an aggregate component and a hydrocarbon component, saidhydrocarbon component comprising hydrocarbonaceous material saidhydrocarbonaceous material being a liquid material, said systemcomprising:

(i) a mixing vessel for containing a mixture comprising water, saidhydrocarbon bearing composition and buoyant beads having a bareoleophilic surface (as defined herein);

(ii) agitation means for agitating the mixture in said vessel so as toobtain product buoyant beads having hydrocarbonaceous materialassociated therewith;

(iii) recovery means for recovering product buoyant beads;

(iv) bead solvent wash means for contacting said recovered productbuoyant beads with a hydrocarbon solvent for recovering therefrom aliquid hydrocarbon mixture comprising recovered hydrocarbonaceousmaterial and hydrocarbon solvent and so as to obtain solvent washedbeads; (v) treatment means for treating said solvent washed beads toobtain recovered buoyant beads having a bare oleophilic surface; and(vi) means for recycling recovered buoyant beads having a bareoleophilic surface to said mixing vessel. As mentioned above a recoverymeans may, for example, comprise means for the recovery of productbuoyant beads by bead flotation.

Keeping the above in mind, and alternatively stated, the presentinvention relates to

A system for effecting separation of hydrocarbons from a hydrocarbonbearing composition comprising an aggregate mixture in a water slurry inwhich said hydrocarbons are contained comprising:

a means of centrifuging in a 3 phase decanter to remove liquid materialfrom the slurry, so as to obtain a water phase a hydrocarbon phase andan aggregate solids phase.

(ii) a mixing vessel and means for delivery to said mixing vessel ameasured quantity of said aggregate solids, water, and. a measuredquantity of buoyant beads that have (bare) surfaces of oleophilicmaterial

(iii) means for agitating the mixture in said vessel so as to obtainproduct buoyant beads having hydrocarbonaceous material associatedtherewith (i.e., buoyant beads to (the (outer) surface of) whichhydrocarbonaceous material is adhered);

(iv) means for recovering product buoyant beads (e.g. by flotation)

(iva) means for delivering said recovered product buoyant beads to awater wash means to remove any entrained water/solids and followed by anoptional air drying means leading to a subsequent solvent wash means forcontacting said recovered product buoyant beads with a hydrocarbonsolvent for recovering hydrocarbonaceous material from said productbuoyant beads (e.g. as a component of a hydrocarbon fluid mixturecomprising recovered hydro carbonaceous material and said hydrocarbonsolvent) so as to obtain solvent washed beads;

(v) means for recovering (or separating) hydrocarbonaceous materialand/or solvent (e.g. as a hydrocarbon fluid (i.e. liquid) mixturecomprising recovered hydro carbonaceous material and said hydrocarbonsolvent) from said solvent washed beads; and

(vi) means for treating said solvent washed beads (by centrifugation) toobtain recovered buoyant beads having an

(bare) oleophilic (i.e. film free or essentially film free) surface(e.g. a surface devoid of or essentially devoid of any hydrocarbon orsolvent (outer) film, e.g. beads for which at least the surfaces are ofoleophilic material); and

(vii) means for recycling said recovered buoyant beads to said mixingvessel.

The present invention may be effectively exploited for recovering (e.g.extracting) hydrocarbon (aceou)s (material) by the use of(naturally/artificially) buoyant oleophilic (hydrophobic polymer) beads.The buoyant beads may be solid, hollow or a cellular core constructionwith a solid surface. They preferably have a smooth non-porous surface,which exhibits specific surface energetic properties that provides ahigh affinity for hydrocarbons, low interfacial surface tension withhydrocarbons and a spreading factor closest to zero with hydrocarbons.Examples of suitable oleophilic materials that may be used in thefabrication of oleophilic beads are neoprene, urethane, polypropylene,plastics and artificial rubbers.

The buoyant beads may for example be slurried with water and a soilcontaining hydrocarbons, e.g. Athabasca Tar Sands, and may be agitatedto ensure thorough contact of the soil with the beads, the slurrymixture then being allowed to settle. The effect of this agitation is tocause a certain amount of the hydrocarbon that was contained in the soilto come into contact with the oleophilic surface of the beads and toadhere directly to the beads. Upon the mixture settling out, the beadsthrough their natural buoyancy float to the top of the mixture fromwhere they are removed to recover the adhered hydrocarbons.

Repeated treatment of the soil by this process can result in a very highrate of recovery of the hydrocarbons.

In the case of Athabasca Tar Sands, recovery rates of bitumen in excessof 98% have been achieved. In the case of Fine tailings effluent, 91%and 85% reduction of bitumen and naphtha content was obtained.Furthermore this has been done at temperatures ranging from ambient to45.degree. C. and without the use of auxiliary chemicals such as causticsoda, hydrogen peroxide or hydrocarbon solvents (as is required in someprior art processes). In the absence of caustic soda, the tailings i.e.the residual soil or sand, settle quickly so that the water can berecycled in a very short timeframe.

The beads which may be used are buoyant (i.e. they may have a specificgravity that is below 0.5 preferably in the range 0.06 to 0.35, mostpreferably from 0.08 to 0.25) and are preferably of substances which arenaturally hydrophobic and oleophilic and display good compressionstrength and resistance to abrasion.

The beads can be of any suitable composition that will provide therequired buoyancy and adequate durability. For example they couldcomprise hollow bodies of e.g. ceramic or metal, coated with acontinuous layer of oleophilic and hydrophobic material. However,preferably the beads are of a homogeneous organic polymer material asdescribed in the preceding paragraph.

The beads used in the examples hereinafter set forth were of low densityand of roughly spherical shape with an average diameter of about 17 mm,there being approximately 1500 beads per kilogram weight. The beadsshould not be too small since if they are they would not providesufficient buoyancy to effect floatation when coated with adheredbitumen and any contained soil; that is the surface area to volume ratiowould be too high.

Accordingly, it is preferred that the beads have a size in the range 12to 20 mm and a specific gravity in the range 0.080 to 0.35.

The beads may be of various shapes, e.g. spherical, roughly spherical,or egg shaped. While round or roughly spherical beads may be preferable,the shape of the beads is critical, as it must not comprise of any highenergy points which are generated by sharp edges or ridges on thesurface.

The (hydrocarbon) solvents which may be exploited in accordance with thepresent invention may for example be of aliphatic materials low inaromatic content. (Hydrocarbon) Solvents are to be preferred which (forexample) have a tendency to dissolve the bitumen so that it can wash offmore readily from the polymer bead surface. Low boiling point solventsare preferable since with these the evaporation and condensation of thesolvent in the process will require little energy. A solvent may forexample be of an aliphatic material such as an alkane-solvent(hydrocarbon) type material (such as for example naphtha, pentane andhexane; in particular naphtha).

The amount of solvent employed will vary depending upon the type andsolvency strength.

The method of the present invention offers a number of advantages asfollows: (a) no solvent is required than would be the case in aconventional solvent extraction process, (b) the process does notrequire the application of heat, but rather can be carried out at normalatmospheric temperatures, and at temperatures ranging from as low as0.degree. C., to 60.degree. C. thus reducing the cost of heating thewater and hydrocarbon source material as had previously been required;(c) after mixing and separation of the beads, the contained solidssettle in the water in a matter of hours (rather than months or years asis the case with some existing processes); (d) since the solids settlequickly the water can be recycled in the process rather than sent to atailings pond for extended settling periods; (e) the hydrocarbondepleted soils can be sufficiently cleansed for reclamation; and (f) themethod can provide hydrocarbon recoveries, which exceeds existingprocesses without the need to add chemicals such as caustic soda whichwould create further downstream pollution problems.

DESCRIPTION OF THE DRAWINGS

The invention will further be described, by way of example only, withreference to the accompanying figures wherein

FIG. 1 is a schematic representation of an example hydrocarbon recoverysystem in accordance with the present invention having a singlemixing/separation stage;

FIG. 2 is a schematic representation of another example hydrocarbonrecovery system in accordance with the present invention having twomixing/separation stages;

FIG. 3 is a schematic representation of a further example hydrocarbonrecovery system in accordance with the present invention having threemixing/separation stages;

FIG. 4 is a schematic representation of a further example hydrocarbonrecovery system in accordance with the present invention havingcentrifuge and shaker stages;

FIG. 5 is a schematic representation of the system of FIG. 4 whereby aportion of water is recycled via a filtration process.

DETAILED DESCRIPTION

In FIG. 1 (1 stage), the base material which in the example hereindisclosed is Athabasca oil sands fine tailings effluent and mature finetailing pond sludge, is mixed in a mixing vessel 1 to homogenize theblending of the 2 streams and may involve the addition of waterindicated by line 61 which is recycled from the water treatment vessel 6comprising a dynamic sand filtration unit. The blended streams aredelivered to mixer 3 as shown by line 13 which measures a specific flowrate of slurry.

In the vessel 3 the oil sands tailings/water mixture is further mixedwith a measured quantity of said buoyant beads which are in the beadstorage vessel 2 are delivered as indicated by line 23. In the exampledisclosed the beads are molded polymer beads, being roughly of roundedshape.

In the mixer vessel 3 the mixture of oil sands, water and buoyant beadsis thoroughly agitated by a paddle mixer which may comprise of a singleor more shafts onto which are fixed perpendicular to the shaft,perforated paddles of such means and dimensions as to seat the buoyantbeads, during their immersion into the aqueous mixture. The rotationalspeed of the mixer shafts are within the range of 40-150 rpm. For aduration of between 1 and 10 minutes, the beads are swept throughout thedownward sweep of the paddle in the rotation through the slurry toeffect contact with the hydrocarbon coated particles and hydrocarbons insuspension. Hence by seating the beads into the paddles we are able toobtain a prolonged contact time. During this agitation it has been foundthat hydrocarbons are extracted from the oil sand particles in themixture and become adhered to the beads.

The beads and slurry during agitation are being displaced along thelength of the mixer towards the other end where the contents of thevessel 3 flow through an aperture and are displaced to a settling vessel4 as indicated by line 34 and are allowed to separate, whereby duringthis process the coated beads with adhered hydrocarbons float to thetop, and sand and other heavier constituents sinking to the bottom andseparated from the beads by a layer of water.

The recovered solids are moved to the solids underflow vessel or tank 5by line 45 plus the water which is directed to the filtration vessel 6by the line 46 following which some of the water may be returned to theprimary blending vessel 1 via line 61 and the remaining recoveredprocess water can be returned for use as process water in the upstreamoperations via line 62. The hydrocarbon coated beads are then removedfrom the vessel 4 and delivered by a conveyor as indicated by the line47 to a bead washing vessel 7. In the vessel 7 the beads are treatedwith a hydrocarbon solvent (e.g. naphtha) which removes the adheredhydrocarbons (together with any contained oleophilic soil solids). Inthe vessel 7 the beads with adhered hydrocarbons are delivered into areception compartment stage in which the hydrocarbon coated beads arethen conveyed on an incline and subjected to a counter-flow wash ofsolvent in a rotating, internally ribbed, perforated inclined trumelwhich incorporates wash spray heads directing solvent onto the beadswhich are transported upwards in the ribbed trumel (solvent beingsupplied through a line 97 from a solvent tank 9) for a duration(slightly) less than the agitation that occurs in the mixing vessel 3.The liquid contents of the bead washing vessel 7 are distinctlyseparated with the solvent-recovered hydrocarbon layer floating as thetop layer above a water layer. The beads which end up solvent coatedduring this wash stage are allowed to drip dry as they reach the topsection of the inclined trumel and the washed beads (which have a layerof solvent that may still contain minor amounts of dissolvedoil/hydrocarbons) therefrom are delivered via line 710 to a dryer unitalso known as a solvent extractor vessel 10. For example, any solvent onthe surface of the beads may be stripped from the beads during thedrying process by being subjecting the solvent coated beads toappropriate temperature and pressure conditions (e.g. partial vacuum)for the solvent being used. The hydrocarbon layer consisting ofrecovered hydrocarbons and solvent is transferred to the storage tank 8by the line 78 for further processing. As desired or necessaryadditional (i.e. make-up) solvent may be added to the solvent tank 9(via line 119 to make-up for any solvent passing on to storage tank 8.The (pumpable) solvent/recovered hydrocarbon mixture in tank 8 may besent via conduit 818 to a pipeline or by tanker truck or by tanker railcar to a further processing plant.

The beads from the dryer unit 10 are transferred to the bead storagevessel 2 by line 102 following the removal of the solvent which hasrestored the bead surface back to its original condition such that it isclean, bare of hydrocarbonaceous film which would otherwise interferewith the surface energetics of the bead in relation to targetedhydrocarbons in the mixing vessel 3 during agitation as described aboveso as to remove the majority of the hydrocarbons from the feedstockdelivered from vessel 1.

As shown in FIG. 1, the beads are moved successively from left to rightfrom bead storage vessel 2 to the mixer vessel 3 then to the separationvessel 4, to the bead washing vessel 7 and to the bead dryer unit 10 tobe recycled into the bead storage vessel 2.

Water passing through the mixer vessel 1, onto mixer vessel 3, then tothe separation vessel 4 and after separation by settling is delivered tothe water treatment vessel 6 and can be recycled to the mixer 1 by line61 or is redirected to other usage by line 62.

The cleaned sand and soil and the like from the separation vessel 5 willhave a very low content of hydrocarbons and may be sent to a landfillsite or the like for reclamation by line 51.

The mixing vessel 1 in which the oil sand material is first mixed withwater may be supplied with water as indicated by the line 61 if need be.The water in treatment vessel 6 is water recovered from the separationvessel 4.

Referring to FIG. 2 (2 stage), the same reference numerals as mentionedfor FIG. 1 are used to refer to the same elements as in FIG. 1. If thedesired amount (e.g. all) of the hydrocarbon material is not removedfrom the oil sands in a (1 Stage Process) comprising a single agitatingcycle with mixer vessel 3, it is contended to add an additional seriesof mixing/separation process cycles as deemed necessary in staging anadditional mixer vessel 13, separation vessel 14 and separated solidsunderflow vessel 15 as an additional modular processing step, for a 2Stage Process. This setup will comprise of the items that are describedin the 1 Stage Process (including as desired or necessary additional(i.e. make-up) solvent may be added to the solvent tank 9 (via line119), i.e. to make-up for any solvent passing on to storage tank 8)along with this additional modular stage, that will process a slurrythat will be made up of a measured quantity of solids from the separatedsolids underflow vessel 5 and delivered to the additional mixer vessel13 as indicated by the line 513 and a measured quantity of water fromthe separated water treatment vessel 6 as indicated by the line 613,with a measured quantity of said buoyant beads from beads storage vessel2 delivered as indicated by line 213, all of which are delivered to anadditional mixer vessel 13 for an agitation cycle. The beads and slurryduring agitation are being displaced along the length of the mixertowards the end, where the contents of the vessel 13 flow through anaperture and are displaced to a settling vessel 14 as indicated by line1314 and are allowed to separate, whereby during this process the coatedbeads with adhered hydrocarbons float to the top, and sand and otherheavier constituents sinking to the bottom and separated from the beadsby layer of water.

The recovered water from the separation vessel 14 is transferred to theseparated water treatment vessel 6 by line 146 and the hydrocarboncoated beads are then removed from the vessel 14 and delivered asindicated by the line 147 to a bead washing vessel 7. Solids pass vialine 1415 to solids underflow vessel or tank 15.

In the vessel 7 the hydrocarbon coated beads are treated with ahydrocarbon solvent which removes the adhered hydrocarbons (togetherwith any contained oleophilic soil solids). In the vessel 7 the beadswith adhered hydrocarbons are delivered into a reception compartmentstage in which the hydrocarbon coated beads are then conveyed on anincline and subjected to a counter-flow wash of solvent in a rotating,internally ribbed, perforated inclined trumel which incorporates washspray heads directing solvent onto the beads which are transportedupwards in the ribbed trumel the beads with adhered hydrocarbons areagitated with solvent (supplied through a line 97 from a solvent tank 9)for a duration (slightly) less than the agitation that occurs in themixing vessels (3, 13). The liquid contents of the bead washing vessel 7are distinctly separated with the solvent-recovered hydrocarbon layerfloating as the top layer above a water layer. The beads which end upsolvent coated during this wash stage are allowed to drip dry as theyreach the top section of the inclined trumel and the washed beads (whichhave a layer of solvent that may still contain minor amounts ofdissolved oil/hydrocarbons) therefrom are delivered via line 710 to adryer unit also known as a solvent extractor vessel 10. The hydrocarbonlayer consisting of recovered hydrocarbons and solvent is transferred tothe storage tank 8 by the line 78 for further processing. As desired ornecessary additional (i.e. make-up) solvent may be added to the solventtank 9 (via line 119), i.e. to make-up for any solvent passing on tostorage tank 8. The (pumpable) solvent/recovered hydrocarbon mixture intank 8 may be sent via conduit 818 to a pipeline or by tanker truck orby tanker rail car to a further processing plant.

The beads from the dryer unit 10 are transferred to the bead storagevessel 2 by line 102 following the removal of the solvent which hasrestored the bead surface back to its original condition in that it is,bare of hydrocarbonaceous film.

If an additional stage (see FIG. 3) is required to further removebitumen from the solids from the separated solids underflow vessel 15,then in addition to the above configuration, another stage comprising ofan additional series of mixing/separation process cycles as deemednecessary by staging an additional mixer vessel 23, separation vessel 24and separated solids underflow vessel 25 as an additional modularprocessing step, for a 3 Stage Process.

The 3 stage setup shown in FIG. 3 may comprise the items that aredescribed in the 2 Stage Process (including as desired or necessaryadditional (i.e. make-up) solvent may be added to the solvent tank 9(via line 119), i.e. to make-up for any solvent passing on to storagetank 8) along with this additional modular stage, that will process aslurry that will be made up of a measured quantity of solids from theseparated solids underflow vessel 15 whereby such measured quantity ofsolids are delivered to an additional mixer vessel 23 by means of line1523 and a measured quantity of water is delivered from separated watervessel 6 by line 623, with a measured quantity of said buoyant beadsdelivered as indicated by line 223 from beads storage vessel 2 aredelivered to an additional mixer vessel 23 for an agitation cycle. Thebeads and slurry during agitation are being displaced along the lengthof the mixer towards the end, where the contents of the vessel 23 flowthrough an aperture and are displaced to a settling vessel 24 asindicated by line 2324 and are allowed to separate, whereby during thisprocess the coated beads with adhered hydrocarbons float to the top, andsand and other heavier constituents sinking to the bottom and separatedfrom the beads by layer of water. The recovered water from theseparation vessel 24 is transferred to the separated water treatmentvessel 6 by line 246 and the hydrocarbon coated beads are then removedfrom the vessel 24 and delivered as indicated by the line 247 to a beadwashing vessel 7.

In the vessel 7 the hydrocarbon coated beads are treated with ahydrocarbon solvent which removes the adhered hydrocarbons (togetherwith any contained oleophilic soil solids). In the vessel 7 the beadswith adhered hydrocarbons are delivered into a reception compartmentstage in which the hydrocarbon coated beads are then conveyed on anincline and subjected to a counter-flow wash of solvent in a rotating,internally ribbed, perforated inclined trumel which incorporates washspray heads directing solvent onto the beads which are transportedupwards in the ribbed trumel. The beads with adhered bitumen areagitated with solvent (supplied through a line 97 from a solvent tank 9)for a duration slightly less than the agitation that occurs in themixing vessels (3, 13, 23). The liquid contents of the bead washingvessel 7 are distinctly separated with the solvent-recovered hydrocarbonlayer floating as the top layer above a water layer. The beads which endup solvent coated during this wash stage are allowed to drip dry as theyreach the top section and the beads therefrom are advanced to a beaddryer via line 710 also known as a solvent extractor vessel 10. Thehydrocarbon layer consisting of recovered hydrocarbons and solvent istransferred to the storage tank 8 by the line 78 for further processing.In terms of further processing it may be suitable to pre-treat therecovered hydrocarbon/solvent solution that is in tank 8 so as to adjustthe solvent concentration in order to meet the pipeline specs of therefinery. This may involve stripping naphtha from the recoveredhydrocarbons by transferring to vessel 18 the hydrocarbons by line 818,recovering the solvent and transferring to the solvent storage vessel 9by line 189 and then pipeline the hydrocarbons from vessel 18 by line1833 onto an oil storage facility illustrated by vessel 33.

From the vessel 7, the beads therefrom (the washed beads which have alayer of solvent that may still contain minor amounts of dissolvedoil/hydrocarbons) are delivered via the line 710 to a dryer unit alsoknown as a solvent extractor vessel 10. The beads from the dryer unit 10are transferred to the bead storage vessel 2 by line 102 following theremoval of the solvent which has restored the bead surface back to itsoriginal condition in that it is, bare of hydrocarbonaceous film.

In this way, under suitable circumstances successive cycles have removedup to 99% of the hydrocarbons contained in the oil sands, the resultingcleaned soil material from the separation vessel 25 will have a very lowcontent of hydrocarbons and may be sent to a landfill site or the likefor reclamation. Solids pass via line 2425 to solids underflow vessel ortank 25. If required it may be advantageous to remove further entrainedwater from the recovered clean sands by means of a hydrocyclone 31 whichis fed by line 2531. The resulting product will comprise a free flowingtan coloured granular material with a very low hydrocarbon content andvirtually no solvent content. The recovered water from the hydrocyclonecan be transferred into a water tank 32 by line 3132 and supplement therecycled water volume that may be required in vessel 1.

With a single agitation cycle lasting from 1-10 minutes in the mixervessel 3 it has been found possible to remove as much as 87% of thebitumen from the high grade oil sands at a temperature of 20.degree. C.and 72% bitumen for low grade of ore.

FIG. 4 is a schematic of another embodiment of the hydrocarbon recoverysystem in accordance with the present invention having a singlemixer/separation stage, with a shaker being used in place of theseparate bead washing and drying stages. This embodiment, has many ofthe same elements and processes as described for FIG. 1, but has thefollowing modifications. Elements numbered the same in FIG. 4 as in FIG.1 are not described again, and reference may be made to the foregoingdescription of FIG. 1 for a full identification of these elements.

In this embodiment (“Shaker Configuration”), feed slurry from mixingvessel 1 travels to 3-phase decanter centrifuge 402, before therecovered solids travel to mixer 3 shown by line 23, along withrecovered water 414. Recovered hydrocarbonaceous material 218 can becycled back into the process as described with respect to earlierembodiments.

In the above described process for FIG. 1, after the separation process,the hydrocarbon beads are removed from vessel 4 and delivered byconveyor 47. In the Shaker Configuration, the bead washing vessel 7 anddryer unit 10 are replaced by shaker 407 and centrifuge 410.

Shaker 7 may be an inclined vibrating screen, with compartmentalizedtroughs to segregate the water and solids in the water wash and airdrying section back into the slurry either in the mixer or in the2-phase centrifuge 411.

The solvent wash bearing hydrocarbonaceous material from the beadsurface is used as a carrier fluid to assist in entrainment of the beadsinto the centrifuge 410. The carrier fluid improves the extractionefficiency of the centrifuge 410, and buffers the beads as they enterinto the centrifuge 410 via line 710. The recovered hydrocarbons andsolvent are sent from centrifuge 410 to storage tank 8.

More generally, the Shaker Configuration includes a system for effectingseparation of hydrocarbons from a hydrocarbon bearing compositioncomprising an aggregate mixture in a water slurry in which saidhydrocarbons are contained including

(iii) a means of centrifuging in a 3 phase decanter to remove liquidmaterial from the slurry, so as to obtain a water phase a hydrocarbonphase and an aggregate solids phase.

(iv) a mixing vessel and means for delivery to said mixing vessel ameasured quantity of said aggregate solids, water, and. a measuredquantity of buoyant beads that have (bare) surfaces of oleophilicmaterial

(iii) means for agitating the mixture in said vessel so as to obtainproduct buoyant beads having hydrocarbonaceous material associatedtherewith (i.e, buoyant beads to (the (outer) surface of) whichhydrocarbonaceous material is adhered);

(iv) means for recovering product buoyant beads (e.g. by flotation)

(v) means for delivering said recovered product buoyant beads to a waterwash means to remove any entrained water/solids and followed by anoptional air drying means leading to a subsequent solvent wash means forcontacting said recovered product buoyant beads with a hydrocarbonsolvent for recovering hydrocarbonaceous material from said productbuoyant beads (e.g. as a component of a hydrocarbon fluid mixturecomprising recovered hydro carbonaceous material and said hydrocarbonsolvent) so as to obtain solvent washed beads;

(v) means for recovering (or separating) hydrocarbonaceous materialand/or solvent (e.g. as a hydrocarbon fluid (i.e. liquid) mixturecomprising recovered hydro carbonaceous material and said hydrocarbonsolvent) from said solvent washed beads; and

(vi) means for treating said solvent washed beads (by centrifugation) toobtain recovered buoyant beads having a bare oleophilic (i.e. film freeor essentially film free) surface (e.g. a surface devoid of oressentially devoid of any hydrocarbon or solvent (outer) film, e.g.beads for which at least the surfaces are of oleophilic material); and

(vii) means for recycling said recovered buoyant beads to said mixingvessel.

FIG. 5 shows another embodiment of the Shaker Configuration withadditional elements added after the separated water treatment stage.Referring to FIG. 5, the same reference numerals as mentioned for FIG. 4are used to refer to the same elements as in FIG. 4.

The process is similar to what is described above, but has the followingmodifications: water flows from the separation process to the filtrationvessel 6. Rather than the water returning to primary blending vessel 1through line 61 and to upstream operations through line 62, therecovered processed water is sent to water filtration vessel 514 vialine 614.

Filtration vessel 514 provides filtration for water leaving the decantercentrifuge 402 and/or the separation process such that it can berecycled back into the feed slurry 1. Recovered water from the 3-phasedecanter centrifuge 402 also flows to the filtration vessel 514 via line214 rather than going to mixer 3.

Recovery rates are dependent upon a number of factors as will bediscussed more fully below:

(a) Base Material

This may comprise various forms of oil sands, oil sands effluent,hydrocarbonaceous shales, heavy oils, produced oil field wastes,refinery slop, wastewater, tank bottom sludge and various types of soilwhich may have been contaminated e.g. as a result of spillages ofhydrocarbon or natural seepages of hydrocarbon.

(b) Solvent

The process can be operated with various solvents for extractinghydrocarbon material such as bitumen or crude oil from the buoyant beadmaterial. Preferred solvents are hydrocarbons which are available atrelatively low costs from an oil refinery, examples being preferablynaphtha, pentane and hexane. For bitumen recovery it has been found thatsolvents which are lower in aromatics (naphtha) are preferable sincethey tend to have a good solvency towards the bitumen and cause it towash off the bead. Lower boiling point solvents are preferable as lessenergy is required to flash off the solvent and recycle the solvent inthe process.

(c) Solvent Quantity

The optimum quantity of solvent used will depend upon the solvent typeand also on the type of material being extracted. In practice the amountof solvent used has been determined by allowing the solvent coated beadsto drain naturally in a perforated container for a period in the orderof 5-15 minutes. It has also been demonstrated that a fine spray at lowpressure will dissolve the hydrocarbon coating very rapidly, therebyreducing the residence time period. In these circumstances it would beexpected that the beads would retain more of the higher viscositysolvents as the solvent layer thickness would increase with viscosity.The ratio of solvent weight to the weight of the beads following thewash process has been determined to be varying with viscosity from about2% to 11% by weight. Preferably the amount of solvent following thedrying stage should be not more than about 0.5% by weight of the beads.

(d) Temperature.

The optimum temperature for extraction can be determined byexperimentation. For extraction of bitumen containing oil sands,evaluations were made by conducting agitation in the mixer vessel 3 atdifferent temperatures. For a single agitation cycle the followingresults were obtained:

Percentage the 

 Temperature C. External 

 all states Agitation Temperature Percentage of 

20 87 40 96

indicates data missing or illegible when filed

In a pilot plant system of apparatus for carrying out the inventionapplicant has used a twin shaft mixer machine designed by BHS Gmbh. Thismachine has six paddles on each shaft which rotate counter to each otherin the direction of rotating from the center outwards to the sidewallsof the mixer body, having a capacity of about 200 liters and beingequipped with an electronic speed control that operates at speeds in therange 40-150 rpm. About 12 kilograms of oil sands with approximately 10%hydrocarbonaceous material and various amounts of beads were added tothe mixer together with approximately 80 liters of 30.degree. C. waterand agitated for times ranging between 5 minutes and 30 minutes. At theend of agitation the coated beads were scooped from the top of the mixerand the remaining slurry discharged from the bottom of the mixer.

The resulting residual hydrocarbon concentration of the sand was below100 ppm and the residual hydrocarbon concentration in the processedwater was below 15 ppm.

Similar testing on tailing pond sludge with an initial concentration of21,000 ppm that were mixed with water to a final temperature of35.degree. C. resulted in residual hydrocarbon levels of <1100 ppm inthe solids and residual hydrocarbon concentration in the process tailingwater <402 ppm.

In a similar test conducted at a temperature of 42.degree. C., onproduced sand from heavy oil operations with an initial concentration of25,000 ppm, the resulting residual hydrocarbon concentration of the sandwas below 100 ppm and the residual hydrocarbon concentration in theprocessed water was below 1 ppm.

Although that which is described in the foregoing, is solely in relationto the recovery of hydrocarbons from soils, it will be understood thatother applications are envisaged for the invention. For example it isbelieved that the use of the oleophilic beads as described above wouldbe effective for removing oil from oil polluted waters, when the beadsare in contact with the oil/water mixture. Likewise the invention couldbe used for recovering hydrocarbons from oily wastes from oil productionoperations such as produced sand.

The invention claimed is:
 1. A method for the recovery ofhydrocarbonaceous material, said hydrocarbonaceous material being in anaggregate mixture in a water slurry, said method comprising the stepsof: (a) centrifuging said aggregate mixture in the water slurry toremove liquid material from the slurry, so as to obtain a water phase, ahydrocarbon phase and an aggregate solid phase; (b) agitating saidaqueous mixture comprising water, said hydrocarbonaceous material andbuoyant beads having a bare oleophilic surface so as to obtain productbuoyant beads having hydrocarbonaceous material associated therewith;and (c) recovering product buoyant beads.
 2. A method as defined inclaim 1 wherein step (c) comprises a bead flotation step for therecovery of said product buoyant beads.
 3. A method as defined in claim1 further comprising (d) washing said product buoyant beads to removeentrained water and/or solids; and (e) further washing said productbuoyant beads from step (c) with a hydrocarbon solvent so as to recoverhydrocarbonaceous material therefrom so as to obtain solvent washedbeads.
 4. The method of claim 3, further comprising (e) treating saidsolvent washed beads by centrifugation to obtain recovered buoyant beadshaving a bare oleophilic surface; and (f) recycling said recoveredbuoyant beads.
 5. The method of claim 1 wherein said beads have aspecific gravity in the range of from 0.080 to 0.35.
 6. The method asclaimed in claim 1 wherein said beads have an average width in the rangeof from 5 to 20 millimeters.
 7. The method as claimed in claim 1 whereinsaid beads have a specific gravity in the range of from 0.080 to 0.35and wherein said beads have an average width in the range of from 5 to20 millimeters.
 8. A system for the recovery of hydrocarbonaceousmaterial, said hydrocarbonaceous material being in an aggregate mixturein a water slurry, said system comprising: (a) a means for centrifugingto remove liquid material from the slurry so as to obtain a water phase,a hydrocarbon phase and an aggregate solid phase; (b) a mixing vesseland means for delivery to said mixing vessel a measured quantity of saidaggregate solids, water and a measure quantity of buoyant beads having abare oleophilic surface (c) agitation means for agitating said aqueousmixture in said mixing vessel so as to obtain product buoyant beadshaving hydrocarbonaceous material associated therewith; and (c) recoverymeans for recovering product buoyant beads.
 9. A system as defined inclaim 8 said recovery means comprises means for the recovery of saidproduct buoyant beads by bead flotation.
 10. A system as defined inclaim 8 further comprising means for delivering said recovered productbuoyant beads to a water wash means to remove any entrained water and/orsolids.
 11. A system as defined in claim 10, further comprising airdrying means downstream from said water wash means.
 12. A system asdefined in claim 11 further comprising bead solvent wash meansdownstream from said drying means for contacting said recovered productbuoyant beads with a hydrocarbon solvent so as to recover therefrom ahydrocarbonaceous material and hydrocarbon solvent so as to obtainsolvent washed beads.
 13. A system as defined in claim 12, furthercomprising means for treating said solvent washed beads bycentrifugation to obtain recovered buoyant beads having a bareoleophilic surface.
 14. A system as defined in claim 13, furthercomprising means for recycling said recovered buoyant beads to saidmixing vessel.
 15. A system as defined in claim 8, further comprising afilter for filtering waste water from said centrifuge and recycling saidfiltered water back to said mixer.